Process of dyeing cellulose ethers



Patented Apr. 21,1931

UNITED STATES PATENT OFFICE HEINZ EICHWEIDE AND ERICH FISCHER, 0F HOCHST-ON-THE-MAIN, GERMANY, AS-

SIGNORS T0 GENERAL ANILINE WORKS, INC., 01 NEW YORK, N. Y, A CORPORATION OF DELAWARE PROCESS OF DYEIN'G CELLULOSE ETHEZBS No Drawing. Application filed November 9, 1925, Serial No. 68,026, and in Germany November 25, 1924.

It is known that for dyeing cellulose esters or ethers, particularly acetate silk, there are prominently suitable those of the monoazo dyestuffs which are neither of a very prono'unced acid character nor of a very pronounced basic character.

Now we have found that basic monoazo dyestufis of the general formula:

R N=NR2 in which R represents a substituted aromatic radicle containing in the nucleus not more than ten carbon atoms, at least one substituent being a sulfamino group, and R represents a substituted aromatic radicle containing in the nucleus not more than ten carbon atoms, at least one substituent being a group which contains a trivalent nitrogen attached to the aromatic nucleus, are eminently suitable for the dyeing of cellulose esters. These dyestufi's give intense dyeings of excellent properties as to fastness.

The following example will serve to illustrate our invention l kilogram of acetate silk is introduced into a dye bath of 20-25 liters in which 30 grams of the hydrocloride of the dyestufi of the following formula:

mums-Gnz-nQnm foregoing example is used, for instance, the dyestufi'of the following formula:

from diazotized 2-nitro-1-aminobenzene-4- sulfamide coupled with m-toluidine, an intense orange tint is obtained, whereas for in,- stance the dyestufl of the following formula:

mnosOnq-ngnm mula:

. R1 in which R represents a substituted aromatic radicle containing in the nucleus not more than ten carbon atoms, at least one substituent being a sulfamino group, and R represents a substituted aromatic radicle containing in the nucleus not more than ten carbon atoms, at least one substituent being a group which contains a trivalent nitrogen attached to the aromatic nucleus.

2. Process. of dyeing cellulose ethers, which consists in dyein these others with a monoazo dystuifs of the ollowing formula:

Y om mN-me-O-n-N-QNH,

O-llkyl 3. As new products cellulose ethers dyed, with basic monoavzo dyestuffs of the general formula R1 N N R2 in which R represents a substituted aromatic radicle containing in the nucleus not more than ten carbon atoms, at least one substituent being a sulfamino group, and R represents a substituted aromatic radicle containing in the nucleus not more than ten carbon atoms, at least one substituent being a group which contains a trivalent nitrogen attached to the aromatic nucleus.

4. As new products, cellulose ethers dyed with basic monoazo dyestuffs of the following formula:

In testimony whereof, we aflix our signatures.

HEINZ EIGHWVEDE. ERIOH FISCHER. 

